content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2013, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
   * Other names may be trademarks of their respective owners.]
   *
   * ---------------------
   * DatasetExtension.java
   * ---------------------
   * (C) Copyright 2013, by Michael Zinsmaier.
   *
   * Original Author:  Michael Zinsmaier;
   * Contributor(s):   -;
   *
   * Changes
   * -------
   * 17-Sep-2013 : Version 1 (MZ);
   *
   */
  
  package org.jfree.data.extension;
  
  import java.io.Serializable;
  
  import org.jfree.data.extension.impl.DatasetExtensionManager;
  import org.jfree.data.general.Dataset;
  
  /**
   * Base interface for dataset extensions. A dataset extension typically stores
   * additional information for data items (for example 
   * {@link DatasetSelectionExtension}). Dataset extensions can be implemented in 
   * separate helper objects or as part of a datasets. This allows to extend 
   * older dataset implementations.<br>
   * <br> 
   * The {@link DatasetExtensionManager} class can be used to pair datasets and 
   * external helper objects and allows to treat paired datasets the same way as 
   * datasets that directly implement
   * a datasetextension. 
   * 
   * @author zinsmaie
   */
  
  public interface DatasetExtension extends Serializable {
  
      /**
       * @return the dataset that is extended
       */
      public Dataset getDataset();
      
  }
  